Thrust bearings for chippers



OC. 24, 1933. B SUMNER 1,932,166

THRUST BEARING FOR CHIPPERS Filed July 19, 195o 2' sheets-sheet l I lg' b 1li-1; 'I A [(IIH h l Hl [HIL IHIIH] I1|,I o if@ l s' n v SL V 0 0 371 0075/2 omaf .fa/mfr aman,

Patented Oct. 24, 1933 vvUNITEvk STTS mi"A l Claim.

My invention relates generally to thrust bearings in grinding machines and the like in which accidental excessive thrusts occasioned in their operation must be provided for, and my invention f relates particularly to wood grinding machines of the type generally known as chippers used for cutting up refuse lumber into hog fuel, also for cutting pulp wood into theso-called paper chips in the manufacture of paper.

The chipper comprises, as well known, a rotary cutter head or disc carrying' knives on one face and cooperating with a stationary anvil knife, and the wood to be cut is fed between the knives. In the operation of a chipper, excessive lateral thrust 1.5i is frequently occasioned by ther accidental admissionbetween the knives of a piece of metal or by the substance of a very hard knot in the chunk of wood being ground up. When such happens, unless the excessive thrust so occasioned is in- Zo stantly relieved, serious damage to the machine or its operating parts will result.

Such excessive thrusts are frequently set up in chippers and thus placing the latter out of service for repairs, greatly hampers the work to be done by the chipper.

Therefore the main object of my invention is to provide simple and efficient means for permitting one of the two cooperating grinding elements to instantly recede from the other grinding element when one of said hard substances enters between the knives, and to hold the grinding ele ment which is to be permitted such instantaneous recision normally in grinding position by a frangible element which will break under excessive i box, a frangible bearing plate removably secured on the frame, means connecting said slidable journal box with said bearing plate, such Ymeans adapted for adjusting the shaft axially.

The details of my invention covering the above 55.' objects, incidental features and operation of my strain; in that way providing for the instant reliefinvention are hereinafter fully described with reference to the accompanying drawings.

In the drawings:

Fig. l shows a side viewof myl chipper and illustrates the relative arrangement of its parts;

Fig. 2 shows a fragmentary, enlarged View of the same and illustrates the details of the journal bearing provided withl the frangible thrust element;

Fig. 3 shows a plan view of the chipping machine with the housingremoved, and illustrates further details of the journal bearings; and

Fig. 4 shows an enlarged fragmentary view partly in section taken similarly to Fig. 3 and illustrates in detail the axially movable bearings and the frangible thrust element.

Referring now to the drawings, my chipper comprises a base frame a and housing b supported thereon. A transversely arranged-shaft f is journaled at each end in the base in journal bearings, d, e.

- The shaft f is provided with a driven pulley i and a rotary cutter head or disc g carrying radially arranged knives h on its side face. A stationary anvil knife y" is provided on the frame a to cooperate with the knives h of the disc. The knife j is adjustable and held in position by set screws Z threaded in suitablebosses Z.

The housing b which incluses the disc g and pulley i is provided with an opening above the said stationary knife j and has a hopper-like 'enlargement Vb for holding the blocks of .Wood

to be ground, against the knives h of the disc g.

The said. journal bearings d, e, in which the shaft f is journaled comprise a lower portion d', e formed in the base a and complementary caps 2, bolted thereto by bolts 3, forming therewith bearing surfaces 5, 6 havingoil grooves 7, 8 and chambers 9 and 1G into which the ends of the shaft f project.

Self aligning anti-friction bearings 11, 12 are provided on the shaft ,f Within the chambers 9, 10 and thrust collars 13, 14 are provided on the ends of the said shaft.

The anti-friction bearing 12 is slidable within its chamber 10 and the anti-friction bearing 11 is mounted within a split journal box 15, which is slidable within the chamber 9. Y

An arched bracket s is bolted over the end of the journal bearing d and is provided with a screw t in axial alignment with the shaft f, and threaded into the end of the said journal box l5. The said bracket s is provided with lateral extensions s' on each side of the screw t to which is secured by set screws t2 frangible thrust elelvl (l ments or bearing plates u, seated in an annular groove t adjacent the head of the said screw t.

By this construction, should a tramp piece of metal or hard knot be caught between one of the knives h and the knife fi, which would tend to break the disc or the knives, the increased resulting lateral thrust will be communicated to the shaft f and cause the frangible element u to break and allow the shaft f to move axially and carry the disc and knives h, out of cooperation with the anvil knife y and thus relieve the strain, as illustrated by the broken line position shown at :l: in Fig. 3.

Further, by this construction, the new frangible element may be quickly and conveniently replaced without dismouting any part of the chipper and the shaft f and the disc and its knife may be adjusted relatively to the anvil knife y' by means of the screw t. In short, by this construction, I have provided a chipper which is conveniently adjustable from the exterior and adapted for inspection at al1 times without interfering with the operation of the machine or the necessity of removing any of the parts.

I claim:

In a chipping machine, a frame provided at one end with a stationary journal bearing and at its opposite end with a bifurcate portion, a shaft journaled at ends in said stationary journal bearing, a journal box slidable in said bifurcate frame portion, a shaft carrying one of the chipping elements, journaled at its ends in said stationary journal bearing and `said journal box respectively, an arched bracket bolted to the extremities of said bifurcate portion, a thrust screw threaded insaid bracket, and into said slidable journal box, said arched bracket provided with lateral extensions on each side of said thrust screw, a frangible bearing plate secured to said arched bracket by screw bolts and held against lateral displacement by the screw bolts threaded into said lateral extension, said thrust screw being rotatably mounted in said frangible plate.

THOMAS B.'SUMNER. 

